• Annual Conference of KIPS
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• 2005.05a
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• pp.1661-1664
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• 2005

본 논문에서는 computer-aided analysis 의 일환으로 X-ray 심혈관 조영도를 이용하여 관상동맥의 구조를 보여주는 방법에 대해 제시하고자 한다. 관상동맥 폐색증 환자들에게 시술되는 스텐트 삽입 시술이나 관상동맥 우회로 시술을 할 때에는 X-ray 의 조영 영상이 매우 중요한 시술의 기준이 되고 있으며, 조영 영상에서 혈관을 빠르고 정확하게 인식하는 것은 시술의 필수 조건이다. 이러한 시술중의 혈관구조 인식을 돕기 위하여 본 논문에서는 심혈관 조영 영상으로부터 관상동맥의 골격을 추출하기 위한 방법을 제안한다. 본 논문에서는 혈관 구조 추출을 위하여 3 단계 알고리즘을 제시한다. 첫번째 단계에서는 조영도에서 잡음을 제거하기 위하여 동질영역을 블러링할 수 있는 speckle reducing anisotropic diffusion 을 이용한 이미지 필터링을 수행한다. 이 필터링은 영상내 잡음을 제거하고 혈관의 경계선을 강화하여 정확한 영상인식을 가능하게 한다. 두번째 단계에서는 영상 내에서 보여지는 주요 혈관을 분할하는 것이다. 이 영상분할에는 canny edge detection 과 개선된 영역확장법(adaptive region growing)을 동시에 이용하는 복합적 분할기법이 수행된다. 세번째 단계에서는 형태학적 기법(Morphology)을 이용하여 분할결과의 부족한 부분을 보완하고 골격화를 수행하여 정확한 혈관 구조를 추출해낸다. 실험을 위해서는 정상인의 관상동맥 영상 뿐 아니라 혈관이 가늘어지는 폐색이 관찰되는 환자의 영상에 대해서도 실험하였다. 또한 논문에서 제시한 알고리즘에 대한 검증을 위하여 실험 결과들은 의료진의 감수를 거쳤다.

• Annual Conference of KIPS
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• 2004.05a
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• pp.1637-1640
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• 2004

관상동맥 폐색증 환자들에 대해서 시술되는 stent 삽입 시술이나 관상동맥 우회로 시술 중에는 X-ray 등의 조영 영상이 시술의 기준이 되고 있다. 따라서 조영 영상에서 혈관을 빠르게 인식하는 것은 정확하고 효과적인 시술의 필수 조건이다. 이러한 시술 중 빠르고 정확한 혈관 인식을 위하여 본 논문에서는 심혈관 조영 영상으로부터 관상동맥의 형태를 자동적으로 영상분할하기 위한 방법을 제안한다. 우선 조영 영상에서 혈관을 분명하게 인식하기 위해서는 잡음을 제거하기 위한 필터링이 필요한 데, Anisotropic diffusion을 이용한 필터링은 이미지 내 물체의 경계선을 보존하고, 영역 내의 잡음을 제거하는 데 효과적이다. 정확한 영상분할을 수행하기 위해서는 대부분의 경우 사용자가 영상 내에 관심 영역을 지정하는 인터렉션이 필요하지만 이는 사용자에게 불편함을 줄 수 있다. 따라서 이러한 번거로움을 최소화하고, 정확한 결과를 유도하기 위해서 자동 씨드 영역 추출 알고리즘을 제안한다. 따라서 조영 영상에 필터링을 적용한 후 추출된 씨드 영역과 추출된 에지와 Adaptive region-growing을 복합적으로 사용하는 영상분할을 수행하게 되면 보다 효과적인 관상동맥 영상 분할의 결과를 얻을 수 있었다.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.785-789
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• 2010

The acute technical failure of endovascular treatment of chronic total occlusions is most often due to the inability to re-enter the true lumen after occlusion is crossed in a subintimal plane. True lumen re-entry catheters are very effective at gaining wire passage back to the true lumen and facilitating successful endovascular treatment of chronic total occlusions that would otherwise require open bypass. These case reports describe our initial experiences with a new catheter system (the $Outback^{(R)}$ $LTD^{TM}$ catheter) that is designed to allow fluoroscopically controlled re-entry of the true arterial lumen after subintimal guidewire passage during recanalization procedures of arterial occlusions.

• Journal of the Korean Society of Radiology
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• v.81 no.2
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• pp.409-417
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• 2020

Purpose To evaluate the safety and efficacy of the percutaneous manual aspiration thrombectomy technique to treat thrombotic occlusion of native arteriovenous fistulas. Materials and Methods A retrospective review of 20 patients who underwent percutaneous manual aspiration thrombectomy for native thrombotic arteriovenous fistula occlusion from March 2012 to December 2017 was performed. We evaluated technical and clinical success rates and complications. The primary and secondary patency rates were calculated using the Kaplan-Meier analysis. Results Percutaneous manual aspiration thrombectomy was performed in 20 patients (n = 20) with concomitant balloon angioplasty. The overall technical and clinical success rates were both 85% (n = 17). The native arteriovenous fistulas, based on their site, were the left radiocephalic (n = 13), left brachiocephalic (n = 4), and right radiocephalic (n = 3) fistulas. An underlying stenosis was detected in the juxta-anastomotic venous site (n = 16), outflow draining vein (n = 12), and central vein (n = 4). The primary and secondary patency rates at 1, 3, 6, and 12 months were 100%, 70.6%, 70.6%, and 56.5% and 100%, 94.1%, 94.1%, and 86.9%, respectively. There were no complications associated with procedure. Conclusion Percutaneous manual aspiration thrombectomy is a safe and effective method to treat thrombotic native arteriovenous fistula occlusion.

• Journal of Radiation Protection and Research
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• v.25 no.4
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• pp.191-195
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• 2000

This study was undertaken to estimate the exposed dose of the medical personnel during the intracoronary radiotherapy procedure as a part of ongoing SPARE (Seoul National University Hospital Post-Angioplasty Rhenium) trial. Data of thirty-four patients among forty-two irradiated patients participating in this trial due to coronary artery stenosis were retrospectively analyzed. Intracoronary radiotherapy was delivered to the patient immediately after angioplasty ballooning. Prescribed dose was 17 Gy to media of the diseased artery and was delivered with $^{188}Re$ filled balloon catheter. Dosimetry was carried out with GM counter at eight different points. Ten centimeter and forty centimeter from the patient's heart were selected to represent maximum and whole-body exposed dose of the operator, respectively. Median delivered dose was 111.6 mCi with average treatment time of 576 seconds. Average exposed dose rate at 10 cm and 40 cm from the patient's heart were 0.43 mSv/hr and 0.30 mSv/hr, respectively. Average exposed doses per treatment were 0.07 mSv and 0.05 mSv for 10 cm and 40 cm from the patient's heart, respectively. Exposed doses measured are much lower than recommended limit of 50 mSv for radiation workers or 1 mSv for general population in ICRP-60. This study proves that current method of intracoronary radiotherapy incorporated in this trial is very safe regarding radiation protection.

• Journal of the Korean Society of Radiology
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• v.84 no.2
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• pp.483-488
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• 2023

Iatrogenic injury of the vertebral artery during cervical spine surgery though uncommon is critical. With advances in interventional endovascular techniques, the therapeutic approach for vertebral artery injuries has changed. Nonetheless, an established strategy for their management is lacking. We report a case of pseudoaneurysm due to vertebral artery injury, during cervical spine surgery for a tumor, that was treated successfully with endovascular coiling in a plug-and-patch fashion after triple stenting failed.

• Journal of Chest Surgery
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• v.37 no.11
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• pp.911-917
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• 2004

Background: There are limited number of reports on May-Thurner syndrome (Iliac vein compression syndrome) in Korea, We analysed the clinical features, diagnostic modalities and endovascular treatment of May-Thurner syndrome. Material and Method: We reviewed 12 cases of May-Thurner syndrome between March 2001 and June 2003. Mean age was $57.6\pm2$ years. We were used in venography, color doppler and computed tomographic angiography as diagnostic modalities and in thrombolysis, thrombectomy, angioplasty and stent insertion as endovascular treatment. Result: Clinical features showed edema of lower extremities in 4 patients, pain of lower extremities in 1 patient, edema with pain in 5 patients, and all in 1 patient. In one patient, he did not have any pain and any edema of lower extremities but was diagnosed as May-Thurner syndrome using venography due to varicose veins on lower extremities. Diagnostic modalities included venography, computed tomographic angiography in all patients with clinical presentation except in one patient and color doppler was only performed only in 4 patients. Four kinds of endovascular treatment were performed for May-Thurner syndrome, angioplasty in 11 patients, stent insertion in 10 patients, thrombectomy in 9 patients and thrombolysis for 7 patients. Nine patients were followed up and we can show good blood flow in Left iliac vein for 7 of 9 patients. Conclusion: it is necessary to recognize the possibility of May-Thurner syndrome in Deep vein thrombosis patients and we should use a variety of modalities to diagnose May-Thurner syndrome. Finally, endovascular treatment is a safe and effective therapy for May-Thurner syndrome.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.747-752
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• 2010

Surgical repair of thoracoabdominal aortic aneurysm (TAAA) remains a formidable challenge associated with significant rates of mortality and morbidity, especially in patients with high risk. Use of endovascular stent graff in aortic aneurysm disease is now accepted as an alternative treatment to surgery. But the saving of visceral arteries is the chief obstacle to endovascular repair of TAAA. We successfully treated two patients of TAAA with high risk by hybrid procedure including open visceral debranching and concomitant endovascular aneurysm exclusion.

• Journal of the Korean Society of Radiology
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• v.84 no.4
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• pp.792-808
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• 2023

Trauma to the head and neck region can have serious consequences for vital organs such as the brain, and injuries to blood vessels can cause permanent neurological damage or even death. Thus, prompt treatment of head and neck vessels is crucial. Although the level of evidence is moderate, an increasing amount of research indicates that endovascular treatments can be a viable alternative to traditional surgery or medical management. Embolization or reconstructive endovascular procedures can significantly improve patient outcomes. This article provides an overview of various endovascular options available for specific clinical scenarios, along with examples of cases in which they were employed.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.230-234
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• 2024

Interventional recanalization is an effective treatment option for postoperative portal vein occlusion. A transhepatic or transsplenic approach is preferred, whereas a percutaneous transmesenteric route enables antegrade cannulation. Here, we present a case of successful percutaneous transmesenteric recanalization in a patient with a postoperative portal vein graft occlusion.